1. Field of the Invention
The present invention relates to a copier, and in particular to a copier in which reading of an original is carried out simultaneously with formation, on the basis of image data obtained by the reading of the original, of a multicolored transfer image which is to be transferred onto a sheet, and conveying of the sheet is started during the formation of the transfer image, and at a transfer position, the transfer image is transferred onto the sheet.
2. Description of the Related Art
Conventional copiers have been proposed in which, when an original which is to be copied (hereinafter, "original to be copied") is an original for which copying is prohibited (hereinafter, "copying prohibited original"), the copier does not copy the original to be copied (see Japanese Patent Application Laid-Open (JP-A) Nos. 64-61777, 1-285977, 1-285978).
Such copiers judge, from image data obtained by an original reading device, whether the original to be copied is a copying prohibited original. In a case in which the original to be copied is a copying prohibited original, an image outputting means is not activated so that copying is prohibited, and a predetermined message relating to this processing is displayed or the like. In a case in which the original to be copied is not a copying prohibited original, the image outputting means is activated, the image data is processed, and a color copy can be obtained. In this copier, time is required in order to obtain a judgement as to whether the original to be copied is a copying prohibited original. Therefore, the user is forced to wait for a period of time which is even longer than that required from the time a start-copying key is pressed to the time the first copy is obtained, which is a waste of time for users who are not copying copying prohibited originals.
If attempts are made to shorten this period of time from the time the start-copying key is pressed to the time when the first copy is obtained (hereinafter, "first copying time"), a problem arises in that it is not possible to accurately judge whether the original to be copied is a copying prohibited original.
Thus, in order to shorten the first copying time and to accurately judge whether the original to be copied is a copying prohibited original, a method has been contemplated in which the image outputting means is activated while the determination as to whether an original to be copied is a copying prohibited original is being carried out on the basis of the image data obtained from the original reading device. If it is judged that the original to be copied is a copying prohibited original, a portion of the processing being carried out by the image outputting means is changed such that the transfer sheet is completely colored in by a single color and then discharged, or the conveying path of the transfer sheet is changed such that the sheet is guided to a shredder, or the like.
However, printing the sheet in this manner such that it is totally colored in by one color leads to the toner being quickly used up, and further, leads to an increase in the load on the fixing device and other equipment through which the sheet, which is being discharged, passes, which accelerates the deterioration of this equipment. Moreover, if the sheet is to be sent to a shredder or the like, a problem arises in that there is the need to provide the copier with equipment, such as a shredder, which is not originally provided at the copier.